Plate type heat-exchangers having corrugated, zig-zag sheet members



Jan. 23, 1968 EIH RYBIABAUD 3,364,992 Q PALTE TYPE ATEXCHANGERS HAVINGCORRUGATED, ZIG-ZAG SHEET MEMBERS Filed Dec. 22, 1965 4 Sheets-Shet 1Jan. 23, 1968 E. HENRY-B|ABAUD 3,364,992

' PALTE TYPE HEAT-EXCHANGERS HAVING ZAG SHEET MEMBERS CORRUGATED, ZIG- 4Sheets-Sheet 2 Filed Dec. 22, 1965 Jan. 23, 1968 E. HENRY-BIABAUD3,364,992

PALTE TYPE HEAT-EXCHANGERS HAVING CORRUGATED, ZIG-ZAG SHEET MEMBERS Filed Dec. 22, 1965 4 Sheets-Sheet 5 1968 E. HENRY-BIABAUD 3,364,992

PALTE TYPE HEAT-EXCHANGERS HAVING CORRUGATED, ZIG-ZAG SHEET MEMBERSFiled Dec. 22, 1965 4 Sheets-Sheet 4.

fl m Ml i a United States Patent 3,364,992 PLATE TYPE HEAT-EXCHANGERSHAVING CORRUGATED, ZIG-ZAG SHEET MEMBERS Edmond Henry-Biabaud, Paris,France, assignor to Societe Anonyme Andre Citroen, Paris, France FiledDec. 22, 1965, Ser. No. 515,702 Claims priority, application France,Dec. 31, 1964, 3,171

Claims. (Cl. 165-166) ABSTRACT OF THE DISCLOSURE A heat exchanger has anassembly of two planar plates and a sheet member therebetween havingcorrugations with zig-zag peaks and valleys in the planes of and securedto the plates to define two sets of zig-zagging passages separated bysuch sheet member for heat transfer through the latter between fluidsflowing in the respective passage sets. Preferably, two assemblies, asaforesaid, are arranged in spaced parallel relation with partitionsbetween their facing plates defining conduits extending obliquely togeneral directions of the passages to supply and exhaust one fluid atopposed ends of the inner sets of passages, while the other sets ofpassages carry another fluid.

This invention relates to heat-exchangers.

Certain heat-exchangers include, for reasons of weight and bulk, a largenumber of very fine passages; this is the case particularly withheat-exchangers for use in small gas turbines. Usually these passagesare formed by stacking sheets of very thin metal, alternately plane andfolded in the manner of an accordion, and welded to one another.

Such heat-exchangers are submitted during use, to very -high stressesowing to temperature differences which exist between the different partsof the structure; these stresses may even result in the destruction ofthe heatexchanger. Moreover, it is impossible, without recourse to verythick sheet metal, to use the folds as primary heat-exchange surfaces,that is to say to cause the passage from one side to the other of thefolds, the two fluids between which it is desired to exchange heat.These exchangers are necessarily secondary surface heat-exchangers, acommon fluid passing between the two sides of the folds.

The present invention has for its object, a heat-exchanger whichovercomes the disadvantages outlined above.

According to the present invention there is provided in aheat-exchanger, a corrugated chevron structure defining at least oneheat-exchange surface.

A chevron structure of corrugated form is formed from a plane orlightly-ribbed sheet, which is folded and of which the folds arecorrugated. The walls of the folds are constituted by cylindricalsurfaces of which the generating lines are orientated in two differentdirections, and are separated from one another by corrugated passages ofwhich the general direction is perpendicular to the two directions ofthe generating lines. The fold lines are all contained in twoparallelplanes or faces of 9 the structure. The perpendicular direction to thegeneral direction of the corrugated passages and parallel to the facesconstitutes the length or the breadth of the base plate and it will betermed hereinafter, for simplification, the longitudinal direction ofthe structure, whilst in practice it may be orientated 'to the breadthof the structure. The chevron structures which are also corrugated aredescribed particularly in French Patent No. 1,106,780 of June 10, 1954.V

In a first-embodiment, the heat-exchanger has secondary surfaces andcomprises a series of corrugated chevron structures separated from oneanother by sheets situated in the planes of the faces of the structures,the latter being orientated alternately in two perpendicular directionsto one another, means for causing a first fluid to pass in the passagesof the structures orientated according to a first direction and meansfor causing a second fluid to pass in passages of the other structures.

In a second embodiment, the heat-exchanger has primary surfaces andcomprises at least one chevron structure on at least one of the faces ofwhich a sheet is secured, and means for causing two fluids to passthrough the structure.

The heat-exchanger need include only one structure and a single plate,the passages formed between the structure and the plate being connectedto two headers, whilst the external passages are open. One embodiment ofthis kind is suitable for the exchange of heat between a liquid and agas, for example a central heating radiator.

The exchanger may also include a partition structure disposed betweentwo plates, each group of passages formed between the structure and oneof the plates being connected to two headers.

The exchanger with primary surfaces may include several chevronstructures in parallel. These may, for example, be separated from oneanother by boxes, the headers of each structure being in communication,at one of their ends with the general or main header. In a modification,two chevron structures may be assembled, by being joined together in thedirection perpendicular to the faces but nested one within the other insuch a manner that an interrupted duct is formed between the twostructures.

In one particular embodiment, the exchanger includes two partitionstructures which are disposed each between two plates and are placedwith respect to one another, with the interior walls separated byoblique partitions which define the passages in communication with theinterior ducts of the structure by openings provided in the interiorplates.

Various embodiments of heat-exchangers according to the invention willnow be described, by way of example, with reference to the accompanyingdiagrammatic drawings, in which:

FIGURE 1 shows a fragmentary elevation of a first embodiment;

FIGURE 2 is a fragmentary section on line IIII of FIGURE 1;

FIGURE 3 is a fragmentary section on the line III- III of FIGURE 1;

FIGURE 4 is a section on line IVIV of FIGURE 6 of a second embodiment;

FIGURE 5 is an end view of the second embodiment;

FIGURE 6 is a section on line VIVI of FIGURE 4;

FIGURE 7 is a section on the line VII-VII of FIG- URE 4;

FIGURE 8 is a cross-section of the third embodiment;

FIGURE 9 is a view, partly in section, one'line D(IX of FIGURE 8;

FIGURE 10 is a view similar to FIGURE 8 'of a modification;

FIGURE ll is a section on line XIXI of FIGURE 12 of a fifth embodiment;

FIGURE 12 is a sectional view on line XII-XII of FIGURE 11;

FIGURE 13 is a view, in elevation with parts broken away and partly insection of a sixth embodiment; and

FIGURE 14 is an end view, likewise withparts broken away and partly insection.

The heat-exchanger shown in FIGURES 'l to 3 is of the type withsecondary surfaces and arranged forcross-flow. It is formed by a seriesof corrugated chevron structures 1 and 2 separated from one another byplates 3 situated secured together by welding. Corrugated passages 4 orcommunicating with headers (not shown), are thus formed between twosuccessive folds of a structure 1 or 2 and the adjacent plates 3. Thestructures 1 and 2 which are alternate, are orientated in twoperpendicular directions in such a manner that the passages 4 and 5 arelikewise orientated in two perpendicular directions. The passages 4 areused for the passage of a fluid (hot gas for example) and the passages 5for the passage of another fluid (cold air for example) as indicated bythe arrows in FIGURES 2 and 3. p

The embodiment of FIGURES 4 to 7 is of the primary surface type andoperates on the counter-flow principle. It is formed by two partitionedstructures with corrugations 6 which have the same orientation and areeach interposed between two plates 7 and 7a; passages of substantiallytriangular section 8 and 8a are thus formed between each of thestructures and the plates 7 and 7a' (see FIG- URE 7). The plate 7 has asize at least equal to that of the structure whilst the plate 7a has asize somewhat smaller. The two structures are disposed one upon theother, with the plates 70 opposite one another, whilst being separatedby oblique partitions 9 defining ducts 10 and 10a of which at the mostonly one end discharges to the exterior of the exchanger, this end beingthe entry for the ducts 10 and the exit for the ducts 10a; they areassembled together by means of connecting pieces 11 which are disposedbetween the edges of the perpendicular structures at their folds andconform to one another in such a manner as to block the ends of thepassages 8a (FIG- URE 5). Owing to the smaller size of the plates 7a,the passages 8a of the two structures are in communication at one oftheir ends with the ducts 10, and at their other ends with the ducts10a.

The passages 8 are interposed in the circuit of one of the fluids, forexample the hot gas. For their part, the ducts 10 and 10a are interposedin'the circuit of the other fluid, for example cold air. Under theseconditions, this air passes through the ducts 10 then enters thepassages 8a, traverses the passages 8a in counter-flow to the gas whichcirculates in the passages 8 and finally is discharged to the exteriorof the heat-exchanger through the ducts 10a.

This heat-exchanger eifectively resists difierences in pressure whichmay exist between the passages 8 and 8a. It is possible to assemble anynumber of elements or structures, by simple superposition.

It is possible to construct on the same principle heatexchangerssuitable, in particular, when one of the fluids is a liquid.

It is thus, that the heat-exchanger shown in FIGURES 8 and 9 includes astructure with corrugated partitions 12 disposed between two plates 13and 14 slightly larger than the structure and welded to the latter. Thepassages situatedon one side of the structure communicate through twoheaders 15 and '16 disposed in an extension of theplate 13, with inletducts and outlet ducts 15a and 16a; similarly, the passages situated onthe other side of the structure communicate with two headers 17 and 18with inlet ducts. and outlet ducts 17a and 180. This exchanger issuitable for heat-exchange between two liquids and by causing one toenter through the duct 15a and the other through the duct 18a theliquids circulate in counter-flow,

The embodiment of FIGURE 10 is simpler, in that only the plate 14 andthe headers 17 and 18 have been provided. This embodiment is suitablefor a process of heat exchange between a liquid and a gas. The liquidenters through the header 17 and leaves through the header 18; for itspart, the gas circulates naturally between the-folds of the structure 12and the heat is transferred by radiation and natural convection.

The embodiment of FIGURES 11 and 12 shows an exchanger including severalcorrugated partition structures 19 disposed in parallel. Thesestructures are superimposed whilst being separated from one another byboxes 20 of of one of the two boxes 20. The plates 21 likewise includeopenings opposite the headers 24 and 25, but these are disposed inquincunx relationship with the opening 26.

.In the embodiment of FIGURES 13 and 14 corrugated chevron structures 27are assembled together with a predetermined spacing in the directionperpendicular to the faces, whilst being partially nested in oneanothenin such a manner that their folds face one another, thus forminga series of interrupted ducts 28. Every other one of theducts 28communicates with two headers 29 and 30; the other ducts allowcirculation of a second fluid along the direction of the corrugatedpassages.

The exchangers according to the invention are totally insensitive, inthe longitudinal direction and in the general direction of thecorrugated passages, to expansions and contractions caused bytemperature variations; they have, however certain degree offlexibility. The mechanical strength is thus superior to that of presentday heatexchangers with secondary surfaces. On the other hand, itsdeveloped surface is very large so that its bulk is re duced. Finallyits sides, parallel to the directions of the generating lines, are verystrong, which allows the construction of primary surface heat-exchangerswith extremely thin sheets, and are therefore light.

It will be clear thatthe invention should not be considered to belimited to the embodiments described and shown but it covers, on thecontrary, all modifications.

I claim: a 1. A heat exchanger comprising at least two assemblies eachassembly having two spaced parallel planar plates,

and between said plates, a sheet member having corrugations withparallel, zig-zag peaks and valleys respectively lying in common planesand along which said sheet member is secured to said planar plates todefine with the latter two sets of zig-zagging passages, which sets areseparated from each other by said sheet member, said assemblies being inspaced parallel relationship so that one of said.

passages in each of said assemblies definedbetween said one plate andthe respective corrugated sheet member, so that a first fluid can beintroduced to, and exhausted from said one set of passages in eachassembly by way of said first and second sets of conduits, respectively,the other of said sets of passages in each assembly having openings atthe opposite ends thereof for respectively receiving and exhausting asecond fluid to flow therethrough countercurrent to the first fluid andin heat exchange relation thereto through the corrugated sheet memberbetween said,

sets of passages.

2. A heat exchanger according to claim 1, in which said assemblies arequadrilateral and have first and second pairs of opposed sides, saidconduits of the first and second sets respectively opening at theopposed sides of said first pair, and said openings of said other setsof'passages' in said assemblies being at the opposed sides of saidsecond pair, whereby to facilitate connections to saidconduits and tosaid openings of the other sets of passages.

3. A heat exchanger according to claim 2,.in which said facing plates ofthe assemblies have smaller dimensions in said general directions of thepassages thanthe 5 corresponding dimensions of said corrugated sheetmembers so as to provide for said communicating of said conduits withthe opposite end portions of said one set of passages in each assembly,and connecting pieces extend between said corrugated sheet members atsaid second pair of opposed sides.

References Cited UNITED STATES PATENTS 1,601,637 9/1926 Meigs 165-166 102,780,446 2/1957 Huet 165165 X 2,869,835 1/1959 Butt 165-166 6 2,875,9863/1959 Holm 165166 X 3,196,942 7/1965 Prentiss 165-166 3,216,494 11/1965Goodman 165-166 3,231,017 1/1966 Henderson 165-166 FOREIGN PATENTS687,006 5/1964 Canada. 821,430 10/1959 Great Britain.

EDWARD 1. MICHAEL, Primary Examiner. ROBERT A. OLEARY, Examiner.

M. A. ANTONAKAS, Assistant Examiner.

